Even with MUTE DST–> INT, I still fell into this issue this evening… 
– after months of smooth sailing. I’ve NEVER had this issue with other machines, and I’ve been making tracks on this for nearly three years. Either I’m daft (very likely!) and/or something is fishy about how ‘easily’ this seems to happen.
I have an Akai LPD8 I bought to mute and unmute things during a live set and it works well over usb to midi using a Kenton USB host, however:
The pots send data to they are track volumes, but CC94 (Mute) mutes only and pressing the pad with that CC data again doesn’t unmute, whether in MUTE DST - INT or otherwise, nor does data get sent back to illuminate the controller to show the track state…